How to copy Linesets between scenes?
View Layers
One of the changes in 2.8 from prior is the use of view layers. This is where Freestyle settings now reside
Change up to script (compare with original to see changes)

Use the context view layer as the source, ie make the the source
scene context when running script.  (If more convenient swap this
around and have a hardcoded source and copy into context)

Test script, current default is to Copy settings of view layer with context into view layer named &quot;View Layer&quot; in scene named &quot;Scene.001&quot;
import bpy
from bpy import context 

excludes = ('__doc__', '__module__', '__slots__', 'bl_rna', 'rna_type')

# get the freestyle of context view layer
linesetsFrom = context.view_layer.freestyle_settings.linesets

# copy to scene                 
to_scene  = bpy.data.scenes.get(&quot;Scene.001&quot;)
# into freestyle settings of its &quot;View Layer&quot;
linesetsTo = to_scene.view_layers['View Layer'].freestyle_settings.linesets

for name in linesetsFrom.keys():
    src = linesetsFrom[name]
    dest = linesetsTo.get(name)
    if dest is None:
        dest = linesetsTo.new(name)
    for attr in dir(dest):
        if attr not in excludes:
            print(attr)
            setattr(dest, attr, getattr(src, attr))